As I present this series of articles on various advanced technologies that we've adopted at Sukoneck & Wilson, I don't want to leave out something that may not seem as exotic as lasers or electronic shade-taking devices, but has nevertheless changed our practice of dentistry for the better in dramatic ways.
Let's have a brief look then at the H & H impression technique. This moniker stands for "hydraulic and hydrophobic". The idea is to use hydraulic pressure to move an impression material, that displaces water, all around the teeth and gums. You see, any time we make an indirect restoration- such as crowns, onlays, veneers- any restoration that is made in a dental laboratory, we have a need to generate a highly accurate 3D model of the teeth being restored. We're talking about a few microns, or thousandths of a millimeter, being the equivalent of ten yeards of a football field, just as a way of gaining some appreciation of the scale here.
The H & H impression technique was developed by Dr. Jeff Hoos and materials to carry it off successfully have been developed by Dr. Ray Bertollotti and Danville Engineering.
What a cool company. Very Visceral. And this link points to Dr. Bertollotti's excellent technical explanation of the technique; for the dentists in the audience:
This technique only applies to closed-bite impressions; these are often used for single tooth restorations. For larger restorations and implant crowns we take one full impression of each jaw or arch; that's an entirely different technique.
What happens with H & H is that we use two materials in sequence. They both taste pretty neutral, which is a bigger plus than it might sound at first. (Some of the impression materials that we had back in the 80's tasted like a gumbo of sour milk, dry aspirin and burnt, aged coffee- Gack!)
The first material, light blue, starts out with the consistency of whipped cream- it's just fluffy. Yet it sets to a remarkable hardness. We have our patient open a bit, rinse everything off, and then place the second, darker purple material, in the side of the impression where the treatment has been done. This is the hydraulic part- the purple material flows just everywhere. If there's water or even blood, it just pushes it out of the way. It captures detail like nothing else in dentistry. And- this benefits you, our patients, because everything we do for you fits so beautifully.
Here's an H & H impression:
And in a closeup we can see that the material even flows under the gumline to the extent that the gums are separate from the teeth. At the arrow the material even looped around under the molars, through the space where we floss.
H & H impressions. They may not be lasers or digital maps or electronic shadetaking devices- but they're still rocket science!